PDF Editor for Android

What it does

PDFMason covers the whole editing loop on one phone. Nothing below needs a server, a second device, or a re-upload. Tiers are stated plainly: reading, annotation and page tools are free; text editing, OCR and PDF-to-Office are paid.

Reading and diagnosis

Open PDFs from the system picker, including password-protected files: enter the password and the file opens like any other. On open, a built-in diagnosis classifies every page as native text, scanned, mixed, vectorized text, or empty, detects hidden OCR layers, counts text columns, and grades the document into one of five editability levels with a concrete reason. Full-text search highlights hits with the surrounding line.

• Five-tier editability rating, computed per document, with one of nine specific reasons.
• Document permissions (modify, copy, print) are read and respected — the app disables what the file disallows instead of bypassing it.
• Search runs progressively on long documents and says so when results are truncated.

Text editing of existing content — paid

Tap a text block to select it whole, or long-press a word and drag the handles to extend the selection character by character. Replace an entire block or only the selected fragment, insert or delete blocks, and move or resize text frames. Font family, size and color are editable on the text you touch. When the replacement is longer than the frame, the app offers three outcomes: shrink the font to a suggested scale that fits exactly, truncate the text, or expand the frame. The result stays real text — selectable, searchable, one paragraph.

This is the paid tier, and it is the part almost no Android editor ships: most stamp a new text box over the old line and leave two overlapping texts in the file.

Annotation — free

• Highlight in six colors at 45% opacity.
• Underline and strikethrough, applied line by line so they follow the text.
• Handwritten ink in eight colors; strokes merge into a single undo step.
• Sticky notes and free text boxes.
• Flattened export when annotations must be burned into the page.

Images

Insert, replace, delete, move, scale and rotate images, and adjust their stacking order relative to text and other images. Selection disambiguates by z-order, so an image sitting behind text is still reachable.

Page tools — free

Delete pages, reorder them by drag in a grid, rotate in 90-degree steps, duplicate, insert blank pages, insert pages from another PDF (which may carry its own password), insert an image as a full page, and crop. The app states plainly that cropping only hides content — the cropped object stays in the file.

Forms and signatures

Fill Latin-script text fields; the app writes proper appearance streams so other readers see the value. Non-Latin fields trigger a warning per field before you commit. Checkboxes and radio buttons are marked unsupported. A handwritten signature can be placed — a drawing of your signature, not a cryptographic certificate.

Tools, OCR and conversion

Merge multiple PDFs with per-file passwords and optional page ranges. Split by range, by picked pages, or one file per page. Compress in two tiers, standard and high — and the app says when a compressed result is not worth keeping. OCR (paid) runs on the phone in two output modes: a searchable layer that keeps the scanned image, or editable mode that replaces recognized pixels with real text. Each recognized line is classified as printed or handwritten on the device. PDF to Word, Excel and PowerPoint (paid) runs entirely on the phone, in flowing-text or preserved-layout mode.

Save, undo and recovery

Save as a copy or overwrite the original; the app picks incremental or full rewrite automatically. After writing it re-opens the file and verifies it, then shows a report of what changed — rasterized pages, font substitutions, lost permissions, unusual size jumps. Undo and redo work across the session, and if the app is killed mid-edit, unsaved work is recovered from a draft. Long documents save in the background with progress, and a save can be cancelled.

What makes it different

Most Android PDF apps share one shortcut: they never touch the original content. PDFMason was built around the opposite decision, and five checkable differences follow from it.

It rewrites the original text objects

A PDF stores text as positioned glyphs, not as a flowing string. PDFMason reshapes the replacement line with a text shaping engine, subsets the font to the glyphs actually used, re-embeds it, and writes everything back. The edited paragraph is still one paragraph — not a picture of one.

It diagnoses before you work

The five-tier editability grade and the per-page type are computed when the document opens, so within seconds you know whether a file is directly editable, needs OCR, or cannot be changed at all — before you invest time in it.

It refuses edits it cannot write correctly

If the embedded font cannot draw a character you typed, the edit is refused and the exact characters are named. You never get silent black boxes, wrong glyphs, or dropped characters. A font picker lets you switch and write the edit with a font that covers it.

It works with no network, and proves it

The APK declares no INTERNET permission, and a build check fails if a dependency adds it back. Offline is enforced by the manifest, not promised by a settings toggle. The same design removes the advertising-ID permissions that the bundled OCR engine would otherwise carry.

It saves defensively

Verification after every save, a change report, undo history, and crash-safe drafts. A failed save never damages the source file.

What it doesn't do

The boundaries, in the same words used everywhere on this site:

Password-protected files, browser versus app: “The browser tools can't open password-protected PDFs. The Android app can.”

The browser side is deliberately smaller than the app: “No OCR, no compression, no PDF-to-Word in the browser — yet. We'd rather ship nothing than ship a version that doesn't work.”

Checkbox and radio form fields: “Checkbox and radio-button form fields are marked unsupported in the app. We can change them in memory but the change doesn't survive saving, so we don't pretend otherwise.”

Non-Latin form filling: “Filling non-Latin text fields can produce a file that appears blank in other readers. The app warns you per field.”

Line and arrow annotation shapes were tested on real documents and cut: “We tested it on real documents: it only writes correctly to 33% of them. So it's not in v1.”

Saving very large documents: “A 1,136-page document takes 24–32 seconds to save with verification. It runs in the background and you can cancel it.”

Beyond those, the first version does not include: setting passwords (encryption), redaction of content, batch processing of multiple files, Office-to-PDF, document-wide find and replace, outline or bookmark editing, certificate-based digital signatures, cloud sync, AI chat or summarization, camera scanning, or PDF/A preflight checks. Annotation shapes beyond the cut line-and-arrow case, moving and resizing existing annotations, and an annotation list are also out of v1.

Free vs Pro

The split is by capability, not by a time limit or a file count. Reading, annotation and page tools are free. Text editing, OCR and PDF-to-Office conversion are paid Pro features. The 12 browser tools are free without an account or watermark.

Pricing for the Pro tier is announced at release. Nothing on this page is metered by tokens, watermarks, or daily limits.

Requirements

The requirements are short because the app depends on almost nothing:

• Android 8.0 or later (API 26).
• No Google Play services required. The OCR model ships inside the APK, so Huawei and HarmonyOS devices and de-Googled ROMs get the same features.
• No network connection, ever — the manifest declares no INTERNET permission.
• No account, because there is nothing to register for.
• Files are opened through the system document picker, which grants exactly the chosen file; the app does not request all-files access.

The app is not on Google Play yet. Join the waitlist on the download page and you will get one email when it ships. The offline behavior and the text editing workflow each have their own page.

FAQ